Change-speed gear



29, 1942. kG, BURR 7 2,906,543

CHANGE-SPEED GEARs y v Filed Feb. 12, 1959 Pigt 16 fc u i n l' fr F192 fi l, Fis/f5 N fnverlffaf:

"Patented Dec. 29,1942

, UNITED STAT-E s -fPTE-N CHANGE-SPEED GEAR t Gustav Burr,Frielrlchshafenfon-tlielliodensea`v Germany; vested .in the vAlienProperty Custodian l Apbl'iauon February 12, 193s, serial No.,19o,3ozf

In Germany March 1,1937

v 8 Claims. (CLN- 337) In change speed gearing,r more particularly for4motor vehicles, in which the various .trains are engaged and disengagedby the slidingofgear parts, for example sliding `gear wheels O rcouplingfv-s'leeves, the sliding gearl parts frequently jump out 4ofengagement; particularly .after a certain length of service.Thereasonsfor ythis are the wear of the bearings and `journalsand V theresulting displacements and sagging orV distort'ion` of thevariousparts,

of -the centre ,displacement produced by wear; in the case Of journalsmounted one within the The consequence other, is that the powertransmittingsurfaces are constantly under -the ,action of',sliding'f-forces acting in adirection fordisen'gagement. These forcesare. greater, the greateris thev load Onthe n gearing. Saidforces actingforidisengagement e cannot be counteredk by the `normal forces-holdingthe sliding gear part'in engagement.

eliminated by thev guide elements 'for the longitudinal guiding lof thesliding gear parts being setl obliquely on theirsh'aft elementsrelatively to the. axis, inv such amanner'that a. sliding force istransmitted from vthese guide elements to .t

said sliding gear parts for keeping the latter in engagement.' Theinclination ofthev guide elements on the shaft -extends Oppositey t0 thedirectionof rotation, viewed from thedriving side;

The construction may be such that only the guidev flank which drives inthe case Of forward vehicle travel is set obliquely to the shaft ac`'LAl the "coupling members jumping out ofengagement,.the guideL flanksaccording to the. invention are convcrgently set obliquely to the axisof thev shaft. `Expediently,t hey Obliquity of the v guide flank or ofboth flanks may be .provided only on that part of the shaft von whichthe' vsliding gear issituated i-n theengaged position.

rIfh-einventionl is shown diagrammaticallyy 4in Figures 1 to v5 -ofY theIaccompanying drawing. v

Figure 1 is a planview, partly ir. section, showing a portion'A of achange'speed gear selected by waye of' example. Y

. Figures-25 inclusiveare diagrammatic plan views of the guideelementsfor the movable clutch member, associated with the change speed gear.

' on shaft' elementi.

besidethe gearwheel- IIl.

cording to the invention, since only said -flank has to transmitconsiderable torques, while theK other flank is only stressed for thetransmission of smaller forces and then normally only fora vshort time.For this reason,.a;further construction may also besuch .that both guideflanks arelset obliquely to the shaftand parallel to one another,onlythe flank which drives in the'case of forwardvehicle travel havingthe Obliquity in accordance with the invention.. Manufacture is therebysimplified.

. If considerabletorques-are ktolbe transmitted .v by thefguide flanksin both. directions without"- I denotes a shaft part ofthe 4main shafttrain of a change speed- 'gear having fast. on it a gear wheel 2, on theright-hand side of Iwhich isa dog clutch member 3., land 5-inerenti-friction bear i l ingsr for theashaft part` I or the `gearwheel 2. y Mounted-in the shaft element I by 'means Of f a small `rollerbearin`g, 1-fisa-shaft ,elementv ,6. 8 isthesliding' clutchf membercomplementary "to the dog clutch member). .Provided onthe left-hand endof shaft elementV are guide elements!! whichvguider thesliding couplingsleeve 8v on said shaft element and'which are set obliquelyfwith respectto the axis of the shaft element 6 `Y'Iheobliquity has,A beenexaggerated to make it clearerf -IU ris another gear wheel fast yil is abearingmounted jI3,is a, partof thelay shaft of this gearing.

,Thisshaft part isjournalledin the 'bearings I4 and I5, On the1efthandend,'the gear. wheel I6 is fast upon the shaft element I3, whileOn the right-hand end of shaft element I 3 are likewise provided obliqueguide elements Il on which the gear wheel 'I8 is adapted to slide. f

Figres 2 and-`3' show constructions in which only the ldriving guideflank is set obliquely.

v"I'he'angle representing the Obliquity is denoted by a, but in thiscase also it has been shown on an exaggerated scale for thev sake ofclearness of representation. In Figure 2, the Obliquity of the'drivingflank extends 'over the entirevl length of vthe guide` elements, andy inFigure 3 approximately Onlyover the length on which the sliding gearvelement is situated in the engaged'position.` Figurefff showsan'oblquityof both guide flanks parallel to one another, while FigureA 5 shows aconvergent Obliquity of the guide fianks.

In) the construction according tO'Figure 5, the arrangement is likewisesuch that the Obliquity of the guide flanks is provided approximatelyonly over the part of the shaft on which the sliding gear element issituated in they engaged position. This construction has the advantagethat the clearance necessary for disengagement, on account of thenon-parallel flanks, is not unnecessarily increased. In the constructionaccording to Figure 5, both the driving and driven flanks transmit tothe sliding gear element, depending upon the particular direction ofrotation, sliding forces which keep the gear element in engagement. Theconstruction may also be such that the obliquities extend over theentire length of the guide elements, as shown in Figure 6 of thedrawing.

In accordance with the invention, it is possible in a simple mannerwithout any special additional measures and devices. but merely by theproposed Obliquity of the guide elements, to prevent with certainty thejumping out of engagement of coupling members which has been found to bevery disadvantageous in the con y structions known heretofore.

I claim:

`1. In a change speed gear, a shaft element with longitudinal guidesplines formed thereon, one lateral flankof each splinebeing truly axialand at least a portion of the other being set obliquely relatively tothe axis-of the shaft element.

2. In a change speed gear, a shaft element with longitudinal guidesplines formed thereon, one lateral flank of each spline being partlytruly axial and partly set obliquely relatively to the axis of the shaftelement.

3. In a change speed gear, a shaft element with longitudinal guidesplines formed thereon, each spline being partly truly axial and ofuniform width and partly tapering on each side.

4. In a change speed gear a shaft element with guide splines formedthereon, the lateral flanks of each spline being throughout its lengthinclined in opposite directions relatively to the axis ofthe shaftelement.

5. In a change-speed gear, a shaft carrying a toothed gear-changemember, interengaging guide elements on said shaft and gear-changemember permitting the transmission of torque therebetween and alsorelative displacement of the gear-change member along the shaft, acomplementary toothed gear-change member adapted to be positivelyengaged by said first-mentioned gear-change member when the latter isshifting said flrstfmentioned gear-change member into and out of saidengaged position whether said shaft is rotating or not, the guideelements on said shaft and on said first-named Searchange member havingmutually engaging approximately radially extending faces, certain of thefaces on the guide elements being formed with an inclination withrespect to the normal shifting direction, whether axial or helical, ofthe associated shiftable gear-changemember, the inclination on any oneface of a guide element being continuously in one direction, wherebyduring normal power transmission a force is produced on saidmst-mentioned gear-change member which while not materially affectingthe operation ofsaid gear-shifting means opposes the working out ofengagement of the gearin one position on said shaft, and means fmchangemembers.

6. In a change-speed gear, a shaft carrying a ltoothed gear-changemember, interengaging guide elements on said shaft and gear-changemember permitting thetransmission of torque therebetween and alsorelative displacement of the gear-change member along the shaft, acomplementary toothed gear-change member adapted to be positivelyengaged by said first-mentioned gear-change member when the latter is inoneposition on said shaft, and means for ,shifting said first-mentionedgear-change member into and out of said engaged position whether saidshaft isrotating or not, certain of the guide elements being providedwith convergent inclinations on both faces, the inclination on any oneface of a guide element being continuously in one direction, so thatboth during normal power transmission and during theover-run a force isproduced on said rst-mentioned gear-change member which while notmaterially affecting the operation of said gearV shifting means opposesthe working out of engagement of the gearchange members.

7. In a change-speed gear, a shaft element with longitudinal guidesplines formed thereon, at least one lateral flank of each spline beingset obliquely relativelyto the axis of the shaft element, the two flanksof each spline converging toward one end of said spline.

' 8. The device as set forth in claim 5 in which said continuousinclination is provided only on those portions of said guide elementswhich are in contact with said gear-change member when the latter is inits engaged position, and for the full length of said portions. 1

n GUSI'AV BURR.

